The present invention relates generally to apparatus for ventilating building foundations and the like and, more particularly, to ventilating apparatus which is selectively openable and closable for mounting in a ventilation opening in a building foundation for controlling ventilating airflow to the foundation.
In the conventional construction of single family homes and similar building structures, it is typical to construct a foundation for the structure by which the lowermost floor surface of the structure is elevated from the supporting ground surface leaving a so-called crawl space within the foundation beneath the floor surface. In such building structures, it is important to provide proper ventilating airflow to the crawl space to permit the exhaustion of heat and moisture prevalent in the summer months so that the risk of mildew, rot and similar damage to the floor structure and other structural members of the building is minimized. On the other hand, it is equally important in the winter months to restrict ventilating airflow to a crawl space in such building structures to provide a generally stagnant insulating air mass within the crawl space to minimize heat loss from the building structure.
One common manner of providing control of the ventilation of a building crawl space is the provision of selectively openable and closable ventilating apparatus in ventilating openings formed at appropriate locations in a building foundation. Perhaps the most widely used form of such ventilating apparatus provides a screenbacked metal grid adapted for mounting in a foundation opening, with a pivoting imperforate plate mounted interiorly of the grid and operated by a chain, wire arm, or the like, extending outwardly through the grid for pivotal movement of the plate toward and away from the grid to open and close it to ventilating airflow therethrough. While such ventilating apparatus have been found to operate effectively for their intended purpose, such apparatus present particular difficulties and problems in installation in both brick-type and wood or other siding-type building construction. As will be understood, in both such types of construction, a brick foundation will ordinarily be provided with the ventilating apparatus typically being mounted within a ventilating opening in the foundation by the use of the cement mortar employed in laying the brick foundation. Conventional ventilating apparatus do not provide any structural support for the laying thereover of a subsequent course or courses of brick following the installation of the ventilating apparatus, so that it ordinarily is necessary to place a metal bar or the like across the ventilator and the uppermost brick course laterally adjacent thereto to provide support for the laying of successive brick courses thereabove. In typical siding-type building construction, no brick course is normally laid over the ventilating apparatus once installed in the brick foundation in the above-described manner and, instead, the wood or other siding is placed edgewise directly on the uppermost brick course laterally adjacent the ventilating apparatus. Hereagain, the conventional ventilating apparatus does not provide suitable support for the siding so as to require the use of a metal bar or the like as above described although such bar disadvantageously obstructs the proper edgewise placement of the siding on such uppermost brick course requiring the siding to be notched or otherwise cut to accommodate the metal bar.
The aforedescribed type of conventional ventilating apparatus are otherwise disadvantageous in that they are generally incapable of regulating the degree of opening or closing for ventilating airflow therethrough. Moreover, experience has shown that such apparatus are subject to breakage or loss of the operating wire or chain and unintended separation of the screen as well as rusting or other decomposition of the pivotal connection of the moving plate whereby over time such apparatus often become inoperable. Additionally, such apparatus are difficult to retrofit into an existing building foundation in replacement of inoperable ventilating apparatus and therefore generally can only be installed in the original construction of a building foundation. A more recently developed type of ventilating apparatus utilizes a thermostatic sensing arrangement for automatically operating opening and closing movement of ventilating openings in relation to the ambient temperature so that manual opening and closing operation of the ventilating apparatus is unnecessary. Such ventilating apparatus also has been found to be effective for its intended purpose but is considered to be relatively expensive and therefore has not achieved widespread use.
In contrast, the present invention provides a manually operable foundation ventilating apparatus of a simple and reliably long-lasting construction adapted for easy installation in the erection of buildings of both brick and siding-type construction. In one embodiment, the ventilating apparatus of the present invention is adapted to be readily utilized as a replacement for broken or otherwise worn or inoperable ventilating apparatus. The present invention also provides a novel opening and closing mechanism permitting the ventilating apparatus to be adjustably set to regulate the degree of opening or closing thereof.